Power Module Package

The present disclosure relates generally to electronic circuits package, and more particularly but not exclusively to power module package.

Power modules are employed to provide one or more voltages to various electronic devices. A power module may integrate power integrated circuits (ICs), control ICs, passive devices, etc. Furthermore, to improve integration, the size of the power module needs to be small. In high-voltage applications, high voltages also bring challenges to thermal performance and package of the power module. Therefore, it is desirable to provide a cost-effective power module with high-power density, high-efficiency, and excellent heat dissipation capability in space-constrained environments.

According to an embodiment of the present disclosure, a power module is provided. The power module includes a first lead frame, a first die, a substrate, a second lead frame, and a second die. The first lead frame has a first part and a second part. The first die is arranged on top of the first part of the first lead frame. A first power device is formed on the first die. The substrate is arranged on top of the second part of the first lead frame. The second lead frame is arranged on top of the substrate. The second die is arranged on top of the second lead frame. A first control circuit is formed on the second die, and the first control circuit is configured to control the first power device.

According to another embodiment of the present disclosure, a power module is provided. The power module includes a first lead frame, a first die, a second lead frame, a second die, a substrate, and a third lead frame. The first die is arranged on top of the first lead frame. A first power device is formed on the first die. The second lead frame is electrically isolated from the first lead frame. The second die is arranged on top of the second lead frame. A second power device is formed on the second die. The substrate is partially overlapped with the first lead frame, and the substrate is partially overlapped with the second lead frame. The third lead frame is arranged on top of the substrate. A control circuit is formed on the third lead frame, and the control circuit is configured to control the first power device and the second power device.

According to yet another embodiment of the present disclosure, a power module is provided. The power module includes a first lead frame, a first die, a second lead frame, a second die, and a substrate. The first lead frame includes a first exposed pad and a first DAP. The first DAP is arranged on top of the first exposed pad. The first die is arranged on top of the first DAP of the first lead frame. A first power device is formed on the first die. The second lead frame is located adjacent to the first lead frame. The first lead frame and the second lead frame are separated from each other. The second lead frame includes a second exposed pad and a second DAP. The second DAP is arranged on top of the second exposed pad. The second die is arranged on top of the second DAP of the second lead frame. A second power device is formed on the second die. The substrate is arranged on top of a part of the first lead frame and a part of the second lead frame. A distance between the first DAP and the second DAP is smaller than a distance between the first exposed pad and the second exposed pad.

The use of the same reference label in different drawings indicates the same or like components.

Various embodiments of the present disclosure will now be described. In the following description, some specific details, such as example circuits and example values for these circuit components, are included to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the present disclosure can be practiced without one or more specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, processes or operations are not shown or described in detail to avoid obscuring aspects of the present disclosure.

Throughout the specification and claims, the terms “left”, “right”, “in”, “out”, “front”, “back”, “up”, “down”, “top”, “atop”, “bottom”, “on”, “over”, “under”, “above”, “below”, “vertical” and the like, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that embodiments of the technology described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. The phrases “in one embodiment”, “in some embodiments”, “in one implementation”, and “in some implementations” as used include both combinations and sub-combinations of various features described herein as well as variations and modifications thereof. These phrases used herein do not necessarily refer to the same embodiment, although they may. Those skilled in the art should understand that the meanings of the terms identified above do not necessarily limit the terms, but merely provide illustrative examples for the terms. It is noted that when an element is “connected to” or “coupled to” the other element, it means that the element is directly connected to or coupled to the other element, or that the element is indirectly connected to or coupled to the other element via another element. Particular features, structures or characteristics may be included in an integrated circuit, an electronic circuit, a combinational logic circuit, or other suitable components that provide the described functionality. In addition, it is appreciated that the figures provided herewith are for explanation purposes to persons ordinarily skilled in the art and that the drawings are not necessarily drawn to scale.

1 1 FIGS.A andB 1 FIG.A 1 FIG.B 1 FIG.A 100 100 100 12 142 120 14 144 12 14 142 144 100 12 100 12 12 12 142 12 12 142 120 12 12 14 120 144 14 144 142 a b a b Please refer to.is a side view of a power modulein accordance with an embodiment of the present disclosure.is a top view of the power moduleas shown inin accordance with an embodiment of the present disclosure. The power moduleincludes a lead frame L, a die, a substrate, a lead frame L, and a die. In some embodiments, the lead frames Land Lare configured to support the diesand, respectively. After the packaging of the power module, at least a portion of the lead frame Lis exposed from a molding compound and is configured as the pin(s) of the power module. The lead frame Lhas a first part Land a second part L. The dieis arranged on top of the first part Lof the lead frame L. A power device is formed on the die. The substrateis arranged on top of the second part Lof the lead frame L. The lead frame Lis arranged on top of the substrate. The dieis arranged on top of the lead frame L. A control circuit is formed on the die, and the control circuit is configured to control the power device formed on the die.

12 14 120 In some embodiments, each of the lead frames Land Lincludes copper, copper-alloy, iron-nickel alloy, etc. In some embodiments, the substratemay be a printed circuit board (PCB), a direct bonded copper (DBC) substrate, a direct plated copper (DPC) substrate, a ceramic substrate, etc.

142 142 142 142 144 144 In some embodiments, the power device includes at least one power switch. The power switch may include, but not limited to, a bipolar transistor (BJT), a field-effect transistor (FET), an insulated-gate bipolar transistor (IGBT), a MOSFET, a HEMT, a JFET, a Gate Turn-off Thyristor (GTO), or a Gate-Commutated Thyristor (GCT). The power device is formed on the die. In one embodiment, the dieis a silicon (Si) die. In another embodiment, the dieis a silicon carbide (SiC) die. In yet another embodiment, the dieis a gallium nitride (GaN) die. However, the present disclosure is not limited thereto. In some embodiments, the power switch is a wide-bandgap (WBG) semiconductor switch formed on WBG semiconductor die. In one embodiment, the control circuit formed on the dieis a gate driver configured to provide a driving signal to the gate terminal of the transistor. In alternative embodiments, the control circuit formed on the dieis a controller for the one or more power switches.

100 142 144 100 1 1 FIGS.A andB In some embodiments, the power modulefurther includes molding compounds (not shown in), and the diesandare encapsulated by the molding compounds. The molding compounds provide electrical isolation between the components in the power module.

1 1 FIGS.A andB 1 1 FIGS.A andB 142 12 142 12 120 142 12 120 12 142 Please refer to. In some embodiments, the power device formed on the diegenerates heat during operation, and the lead frame Lconnected to the dieis configured to dissipate the heat. As shown in, the lead frame Lis extended to and arranged below the substrate. Alternatively speaking, in addition to the portion below the die, the lead frame Lalso has an extended portion below the substrate. Accordingly, the lead frame Lhas a large area for dissipating the heat generated by the power device on the die. Thus, the power module in the present disclosure with extended lead frame may provide better heat dissipation.

100 12 12 120 1 1 FIGS.A andB It should be noted that the structure of the power moduleis merely exemplary and does not limit the present disclosure. For example, the lead frame Lmay have shape other than the rectangle as shown in. The lead frame Lmay improve the heat dissipation of the power module as long as it has an extended portion below the substrate.

2 FIG. 200 200 22 242 220 24 244 22 22 22 242 22 22 220 22 22 24 220 244 24 220 22 22 220 200 a b a b is a top view of a power modulein accordance with another embodiment of the present disclosure. The power moduleincludes a lead frame L, a die, a substrate, a lead frame L, and a die. The lead frame Lhas a first part Land a second part L. The dieis arranged on top of the first part Lof the lead frame L. The substrateis arranged on top of the second part Lof the lead frame L. The lead frame Lis arranged on top of the substrate. The dieis arranged on top of the lead frame L. In this embodiment, the substrateis partially overlapped with the lead frame L. Since the lead frame Lhas an extended portion below the substrate, the power modulemay provide better heat dissipation. It should be noted that the arrangement of the lead frames and the substrate described above is merely exemplary, and the present disclosure does not limit thereto. Persons having ordinary skills in the art may adjust the size, arrangement, and location of the lead frames and the substrate according to actual needs.

3 FIG.A 3 FIG.A 1 FIG.A 300 300 32 34 320 36 342 344 346 348 342 344 32 34 12 32 34 32 32 32 34 34 34 342 344 32 34 32 32 34 34 320 32 34 320 32 34 32 34 36 320 346 348 36 320 342 344 346 348 320 a b a b a a In some embodiments, the power module may include two power devices. Please refer to.is a top view of a power modulein accordance with another embodiment of the present disclosure. The power moduleincludes lead frames Land L, a substrate, a lead frame L, and dies,,, and. The first power device is formed on the die. The second power device is formed on the die. Accordingly, the lead frames Land Lare adjacent but separate from each other. Similar to the lead frame Las shown in, each of the lead frames Land Lincludes first and second parts. The lead frame Lincludes the first part Land the second part L, and the lead frame Lincludes the first part Land the second part L. Both the dieand the dieare arranged on the same side of the respective lead frames Land L, i.e., the first part Lof the lead frame L, and the first part Lof the lead frame L. The substrateis arranged on the other side (i.e., the second part) of both lead frames Land L. Alternatively speaking, the substrateis arranged on top of the lead frames Land Land is partially overlapped with the lead frame Land partially overlapped with the lead frame L. The lead frame Lis arranged on top of the substrate, and the diesandare arranged on top of the lead frame L. The control circuit could be arranged on the substrate. In some embodiments, two power switches are formed on the diesand, respectively. In one embodiment, two control circuits are formed on the diesand, respectively, and the two control circuits are configured to control the two power switches. In alternative embodiments, the power module includes one control circuit configured to control the two power switches, and the control circuit is formed on a die arranged on the substrate.

300 320 1 342 346 2 344 348 1 2 36 320 346 348 1 2 36 In some embodiments, the power modulefurther includes electronic components that are arranged on the substrateand are configured to couple to the power devices or the control circuits. For example, electronic components Care coupled to the power device formed on the dieand/or the control circuit formed on the die, and electronic components Care configured to couple to the power device formed on the dieand/or the control circuit formed on the die. In some embodiments, the electronic components Cand Care capacitors, diodes, inductors, and/or other passive components. In some embodiments, the lead frame Lincludes multiple regions arranged on top of the substrate, and the diesandand the electronic components Cand Care arranged on the different regions of the lead frame L.

320 32 34 32 34 32 34 320 32 34 320 In some embodiments, the substratedisposed on top of the lead frames Land Lforms a bridge between the lead frames Land Lsuch that the lead frames Land Land the substratetogether form a U-shaped structure. The lead frames Land Lcorrespond to two parallel arms of the U-shaped structure, and the substratecorresponds to a connection part of the U-shaped structure that connects the two parallel arms.

4 FIG. 4 FIG. 4 FIG. 400 400 42 44 46 441 442 443 444 445 446 420 420 42 44 42 44 42 44 420 Please refer to.is a top view of a power modulein accordance with yet another embodiment of the present disclosure. The power moduleincludes lead frames L, L, and L, dies,,,, and, and a substrate. In the embodiment of, the substratedisposed on top of the lead frames Land Lforms a bridge between the lead frames Land Lsuch that the lead frames Land Land the substratetogether form an H-shaped structure.

5 FIG. 5 FIG. 5 FIG. 500 500 52 54 56 542 544 546 548 520 520 52 54 52 54 52 54 520 Please refer to.is a top view of a power modulein accordance with yet another embodiment of the present disclosure. The power moduleincludes lead frames L, L, and L, dies,,, and, and a substrate. In the embodiment of, the substratedisposed on top of the lead frames Land Lforms a bridge between the lead frames Land Lsuch that the lead frames Land Land the substratetogether form an N-shaped structure.

300 300 600 600 600 620 640 600 620 621 622 623 661 660 640 641 622 620 642 643 681 680 620 640 660 680 620 342 640 344 660 346 680 348 3 FIG.A 6 FIG. 3 FIG.A 6 FIG. 6 FIG. In some embodiments, the power moduleas shown inis a switching circuit that includes two power devices and two control circuits and is configured to provide a switching voltage. For example, the power moduleis the switching circuitas shown in. Please refer toand.is a schematic diagram of a switching circuitin accordance with an embodiment of the present disclosure. The switching circuitincludes power devicesandcoupled in series between a first voltage (e.g., the input voltage VIN) and a second voltage (e.g., the ground voltage GND), and the switching circuitis configured to provide a switching voltage SW. For instance, the power devicehas a first terminalconfigured to receive the input voltage VIN, a second terminal, and a control terminalconfigured to receive a control signal from a terminalof the control circuit. The power devicehas a first terminalcoupled to the second terminalof the power device, a second terminalconfigured to receive a ground voltage GND, and a control terminalconfigured to receive a control signal from a terminalof the control circuit. Accordingly, the power devicesandare coupled in series between the input voltage VIN and the ground voltage GND and are configured to provide the switching voltage SW based on the control signals provided by the control circuitsand. In one implementation, the power deviceis formed on the die, the power deviceis formed on the die, the control circuitis formed on the die, and the control circuitis formed on the die.

3 FIG.A 6 FIG. 3 FIG.A 32 322 322 34 342 344 342 344 342 342 34 1 344 344 34 2 342 34 322 32 344 34 Please still refer toand. In some embodiments, the lead frame Lfurther includes a pad L. The pad Lis configured to receive the input voltage VIN. In some embodiments, the lead frame Lfurther includes a pad Land a pad L. The pad Lis configured to provide the switching voltage SW, and the pad Lis configured to receive the ground voltage GND. The dieis coupled to the pad Lof the lead frame Lthrough a bonding wire W, and the dieis coupled to the pad Lof the lead frame Lthrough a bonding wire W. In some embodiments, as shown in, the pad Lof the lead frame Lis located between the pad Lof the lead frame Land the pad Lof the lead frame L.

600 300 32 34 34 32 34 320 32 34 346 348 6 FIG. 3 FIG.A In some embodiments, the power circuitas shown inis used in a high-voltage application, and the voltage difference between the input voltage VIN and the switching voltage SW is large. Accordingly, for the safe operation of the power module, the lead frame Lreceiving the input voltage VIN and the lead frame Lproviding the switching voltage Lare separated by a safety distance and are electrically isolated from each other, as shown in. However, the distance leaves an empty area between the lead frames Land L. To utilize this area, the present disclosure provides the bridge-type substratearranged on the lead frames Land L, so that more components (e.g., the control circuits formed on the diesand) may be integrated in the power module.

3 3 FIGS.A-C 3 FIG.B 3 FIG.A 3 FIG.C 3 FIG.A 3 FIG.A 3 3 FIGS.B andC 3 3 FIGS.B andC 300 300 322 342 344 32 362 364 362 364 362 342 320 32 34 382 384 382 384 382 344 320 300 364 384 364 384 Please refer to.is a side view of the power moduleas shown inin accordance with an embodiment of the present disclosure.is a bottom view of the power moduleas shown inin accordance with an embodiment of the present disclosure. For the purpose of illustration, the pads L, L, and Las shown inare omitted in. In some embodiments, as shown in, the lead frame Lincludes a die attach pad (DAP)and an exposed pad. The DAPis arranged on top of the exposed pad. The DAPis configured to connect to the dieand is extended to and arranged below the substrate. Similar to the lead frame L, the lead frame Lincludes a DAPand an exposed pad. The DAPis arranged on top of the exposed pad. The DAPis configured to connect the dieand is extended to and arranged below the substrate. In some embodiments, after the power moduleis encapsulated by the molding compounds, and the bottom surface of the exposed padand the bottom surface of the exposed padare not covered by the molding compounds and are configured to connect to a motherboard to transmit electrical signals. For example, the exposed padis configured to receive the input voltage, and the exposed padis configured to provide the switching voltage.

362 382 1 364 384 2 1 2 1 362 382 2 364 384 1 362 382 2 364 384 1 2 362 382 364 384 2 In some embodiments, the DAPand the DAPare separated by a distance d, the exposed padand the exposed padare separated by a distance d, and the distance dis smaller than the distance d. Alternatively speaking, the distance dbetween the DAPand the DAPis smaller than the distance dbetween the exposed padand the exposed pad. In some embodiments, the distance dis the shortest distance between the DAPand the DAP, and the distance dis the shortest distance between the exposed padand the exposed pad. Since the distance dis smaller than the distance d, the DAPsandmay have large area for heat dissipation, and the exposed padsandmay be separated by the larger distance dto satisfy the requirement of safety distance. In some embodiments, the safety distance is determined based on the input voltage, the ground voltage, the switching voltage, etc.

3 FIG.C 1 320 32 34 300 1 320 32 34 As shown in, an area Ais on the back of the substrateand is not overlapped with the lead frames Land L. In some embodiments, the power modulemay further include electronic components that are arranged on area A(i.e., the bottom surface of the substratethat is not overlapped with the lead frames Land L), and thus more components may be integrated in the power module.

7 7 FIGS.A-F 7 FIG.A 7 FIG.B 7 FIG.C 7 FIG.D 7 FIG.E 7 FIG.E 7 FIG.F 710 720 710 1 2 4 5 720 3 6 9 1 2 710 720 1 2 710 720 730 710 720 730 710 720 3 4 792 794 796 798 730 1 4 1 2 3 4 792 794 796 798 1 9 770 1 4 710 720 730 792 794 796 798 are schematic diagrams of an assembly process of the power module in accordance with an embodiment of the present disclosure. The assembly process includes the following actions. As shown in, the lead framesandare provided. Specifically, the lead frameincludes multiple pads P, P, and P-P. The lead frameincludes multiple pads P, and P-P. As shown in, die attached process is performed. For example, two power devices dies Dand Dare attached on the lead framesand, respectively. As mentioned before, the die D/Dis arranged on top of the first part of the lead frame/. As shown in, the substrateis attached on the lead framesand. Specifically, the substrateis arranged on top of the second part of the lead framesand. As shown in, die and passive component attachment is performed. For instance, two controller IC dies Dand Dand the electronic components,,,are attached on the lead frame on the substrate. As shown in, electrical connection processing that couples the semiconductor dies and other components to a circuit is performed. For example, wire bonding process is performed. As shown in, bond wires are formed on the dies D-Dto provide electrical circuit connections for power devices (formed on D/D), controller ICs (formed on D/D), electronic components,,,, other circuitry of the integrated power module, and pads P-P. Molding process is performed as shown in. For example, the molding process includes forming a package structureto encapsulate the power module with the molding compounds by enclosing the semiconductor dies D-D, lead framesand, substrateand electronic components,,,with an opening for the pads/pins (metal terminals) of the integrated power module. Molding compounds can be epoxy molding compounds (EMC). Moreover, lead trimming and/or forming process is performed.

The present disclosure provides a power module with extended lead frames and bridge-type substrate. Since the extended lead frame has large area, the heat dissipation of the power module is improved. In addition, since the bridge-type substrate arranged on top of the lead frames utilizes the area between the lead frames, more components may be integrated into the power module.

While various embodiments have been described above to illustrate the switch circuit of the present disclosure, it should be understood that they have been presented by way of example only, and not limitation. Rather, the scope of the present disclosure is defined by the following claims and includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which would occur to persons skilled in the art upon reading the foregoing description.